EP 1538548 A2 20050608 - Capacitance detecting circuit and method, and fingerprint sensor using the same
Title (en)
Capacitance detecting circuit and method, and fingerprint sensor using the same
Title (de)
Kapazitätsermittlungs-schaltung und -Verfahren, und dieselbe verwendeteter Fingerabdrucksensor
Title (fr)
Circuit et procédé de détection de capacité électrique, et capteur d'empreintes digitales utilisant ceux-ci
Publication
Application
Priority
JP 2003394001 A 20031125
Abstract (en)
In a capacitance detecting circuit, changes in capacitances at intersections between a plurality of row lines and a column line are detected as voltages. The capacitance detecting circuit includes a column-line driver (5) for driving the column line. A code generator (1, 1B) generates code having orthogonality in chronological order. A selection synthesizer selects a certain number of row lines from the plurality of row lines by using the code and synthesizes measured voltages at the intersections between the selected row lines and the driven column line so as to output the synthesized measured voltage. A decoding computation unit (10) separates the measured voltages corresponding to the capacitances at the intersections by performing product sum computation between the synthesized measured voltage and the code.
IPC 1-7
IPC 8 full level
G01B 7/28 (2006.01); G06K 9/00 (2006.01); A61B 5/117 (2016.01); A61B 5/1172 (2016.01); G06T 1/00 (2006.01)
CPC (source: EP US)
G06F 3/04166 (2019.05 - EP US); G06F 3/04182 (2019.05 - EP); G06F 3/0446 (2019.05 - US); G06V 40/1306 (2022.01 - EP US); G06F 3/0446 (2019.05 - EP)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 1538548 A2 20050608; EP 1538548 A3 20060802; JP 2005157643 A 20050616; JP 4387773 B2 20091224; US 2005141263 A1 20050630; US 7078918 B2 20060718
DOCDB simple family (application)
EP 04257305 A 20041124; JP 2003394001 A 20031125; US 98650504 A 20041110